Internationally, over the last 20-30 years, changing the procedures and processes of assessment has come to be seen, by many educators as well as policy-makers, as a way to frame the curriculum and drive the reform of schooling. Such developments have often been manifested in large scale, high stakes testing programmes. At the same time educational arguments have been made about the need to provide students with good quality formative feedback, and informative reports about what they have achieved. The chimera of a perfectly integrated and functioning curriculum and assessment system has been pursued, but such ambition far outstretches systemic capacity; it is neither feasible nor desirable. The national testing and examination system in England is an exemplar case. As national results have improved, much evidence suggests that, if anything, actual standards of achievement are falling, and grade inflation is undermining public confidence in the whole system. The paper will review these issues and tensions, and argue that a different model for developing curriculum and assessment is urgently needed. (Contains 4 notes, 3 tables and 5 figures.)